Abstract: A highly hydrophilic polyurethane article, which is the skeletal network of a cellular polyurethane foam subjected to a reticulation process wherein the polyurethane contains up to 100 parts of a superabsorbent material per hundred parts of polyol used in preparing the polyurethane, is useful in absorbing and holding large amounts of aqueous liquids is prepared by:(a) mixing a polyisocyanate, a polyol and a blowing agent with a finely divided superabsorbent material which is insoluble in a liquid which the material absorbs and which absorbs at least 15 times its weight of said liquid,(b) reacting the polyisocyanate, polyol and blowing agent under foaming conditions to produce a foam of polyurethane which cmprises a multitude of gas cells or bubbles within the polyurethane matrix,(c) curing said foam of polyurethane, forming a cellular structure with windows or membranes of solid polyurethanes present between gas cells or bubbles,(d) removing the windows or membranes by thermal reticulation thereby leaving the

Abstract: Polyurethane foams having improved physical properties are produced by placing a polymerizable polyurethane reaction mixture into a pressurizable chamber, then polymerizing the reaction mixture at an elevated pressure sufficient to prevent the resulting polymer from completely filling the chamber.

Abstract: An improved process for in situ production of a reticulated, open-cell polyurethane foam which comprises reacting a polyester/polyether polyol mixture with an aromatic polyisocyanate having a ratio of isocyanate moieties to aromatic moieties of about 2:1 in the presence of a catalyst and a blowing agent,the improvement comprises:said polyol mixture being(a) 80 to 95 parts by weight of polyester polyol and(b) 20 to 5 parts by weight of polyoxypropylene polyether polyol or a mixed poly(oxyethylene/oxypropylene polyether polyol, each having at least one polymer of ethylenically unsaturated monomers dispersed therein and a stabilizing surfactant for polyether polyurethane foam,and said process produces a polyurethane foam which has excellent strength properties and an exceeding low resistance to air flow.

Abstract: An improved process for in situ production of a reticulated, open-cell polyurethane foam which comprises reacting a polyester/polyether polyol mixture with an aromatic polyisocyanate having a ratio of isocyanate moieties to aromatic moieties of about 2:1 in the presence of a catalyst and a blowing agent,the improvement comprises:said polyol mixture being(a) 80 to 95 parts by weight of polyester polyol and(b) 20 to 5 parts by weight of polyoxypropylene polyether polyol or a mixed poly(oxyethylene/oxypropylene polyether polyol, each having at least one polymer of ethylenically unsaturated monomers dispersed therein and a stabilizing surfactant for polyether polyurethane foam,and said process produces a polyurethane foam which has excellent strength properties and an exceeding low resistance to air flow.

Abstract: Polyurethane foam is modified by a post-treatment process comprising the steps of contacting the polyurethane foam with a swelling agent for the polyurethane foam and interpenetrating the swollen foam with a chemical additive, then shrinking the interpenetrated foam by removing the swelling agent under conditions where the chemical additive remains trapped in the polymeric structure of the foam.

Abstract: The present invention provides a polyurethane foam having significantly improved longevity in a microbiological process in which the foam functions as a support medium for microorganism in a water system containing nutrients for the microorganisms. Also provided is a method of making said improved foam and an improved microbiological metabolizing (e.g., digestion) process employing said improved foam. The present invention is based upon the discovery that enhanced foam life in such a watery, abrasive environment is substantially enhanced if the polyurethane foam formulation has a urea/urethane ratio of less than about 5 and preferably a urethane index of about 100.